Telecommunications networks that provide wireless access (e.g. GSM, UMTS, WiMax, LTE) have developed tremendously over the past years. In such networks, voice and data services can be provided to terminals having a high mobility, i.e. the communication terminals are not bound to a particular location and are freely movable through the area covered by the network. A gateway node of the telecommunications network enables connection to a further network, for example a network based on IP such as the internet.
The availability of such a telecommunications network connected to the further network has resulted in demands for further services, including services that relate to so-called machine-to-machine (M2M) services. M2M applications typically involve hundreds, thousands or millions of communication modules which each act as a communication terminal to the telecommunication network. An example involves the electronic reading of e.g. ‘smart’ electricity meters at the homes of a large customer base over the telecommunications network from a server connected to the further network. Other examples include sensors, meters, vending or coffee machines etc. that can be equipped with communication modules that allow reporting status information to a data processing centre over the telecommunications network. Such devices may also be monitored by the server. The data processing centre may e.g. store the data and/or provide a schedule for maintenance people to repair or refill a machine, meter, sensor etc.
A characteristic of some of the M2M applications is that the exchange of data with the server is infrequent, for example once every day or so for a smart electricity meter.
Typically, there exists an agreement between the operator of the telecommunications network and the owner/operator of the server or data processing centre about the communication parameters applicable for bearers of each of the communication terminals. As an example, such communication parameters e.g. relate to the QoS class and to the maximum bit rate that is allowed for a bearer in the telecommunications network used for supporting a data session between a particular communication terminal and the server or data processing centre. As an example, in GPRS or UMTS telecommunications networks the communication parameters are comprised in a PDP Context for the communication terminal. In other networks, e.g. LTE networks or cable networks, the communication parameters are provided in similar contexts.
It is generally known that communication parameters can be controlled using policy and charging control (PCC) architectures. An example of such a PCC architecture is described in 3GPP TS 23.203. Policy control is a known process in communication networks, whereby a policy control entity indicates to a policy enforcement entity e.g. how to control bearer resources of e.g. an IP Connectivity Access Network (IP-CAN) bearer. Such IP-CAN bearers may include bearers in GPRS or UMTS communication networks, EPS bearers in LTE communication networks, DOCSIS service flows in cable communication networks etc. Policy control may be used for controlling QoS characteristics in a telecommunications network.
Even though the traffic generated by each of the communication terminals is within the agreed limits as specified in the communication parameters (e.g. PDP Context) for a bearer, and even though such limits are strictly enforced in case a terminal would, intentionally or unintentionally, violate a limit, congestion may occur. For example, when a large number of electricity meters, each infrequently exchanging data with the server, attempt to exchange data with the server at a same moment, the connection between the telecommunication network and the server in the further network may be overloaded or congestion may occur in other parts of the telecommunications network. Overload may occur in either or both the uplink and downlink direction, i.e. data transmitted from the terminals towards the server or transmitted from the server towards the communication terminals, respectively.
Currently, the operator of the telecommunications network has no means to efficiently prevent such overload and has no suitable means to control congestion when it occurs.
U.S. Pat. No. 6,865,185 discloses a method and system for queuing traffic in a wireless network includes receiving a stream of packets for transmission in the wireless network. Each packet includes a flow identifier and is assigned to one of the plurality of virtual groups based on the flow identifier. The virtual groups include discrete transmission resources. Each packet is queued in an assigned virtual group for transmission in the wireless network.
Clearly, there exists a need in the art for more flexible congestion control methods.